Preparation process of novel medical acrylic pressure-sensitive adhesive

Abstract

The invention provides a preparation process of a novel medical acrylic pressure-sensitive adhesive, and relates to the field of medical acrylic pressure-sensitive adhesives. The preparation process of the novel medical acrylic pressure-sensitive adhesive comprises the following steps: S1, research on a synthesis process of the medical acrylic pressure-sensitive adhesive, S2, research on biocompatibility of the medical acrylic pressure-sensitive adhesive, and S3, research on a coating process of the medical pressure-sensitive adhesive and a proper adhesive coating amount: adopting butyl acrylate, acrylic acid-2-ethyl ethyl ester and methyl acrylate to prepare the novel medical acrylic pressure-sensitive adhesive. The medical pressure-sensitive adhesive which is used for transparent dressings, is good in viscosity, non-toxic and non-irritating, does not hurt the skin during stripping and has proper water vapor moisture permeability is developed, and the medical pressure-sensitive adhesive which is good in viscosity, non-toxic and non-irritating, does not hurt the skin during stripping and has proper water vapor moisture permeability is prepared by researching the formula proportion of the medical pressure-sensitive adhesive. And a medical pressure-sensitive adhesive having a suitable water vapor permeability.

Description

Technical Field

[0001] The invention relates to the technical field of medical acrylic pressure-sensitive adhesive, in particular to a preparation process of a novel medical acrylic pressure-sensitive adhesive. Background Art

[0002] Medical acrylic pressure-sensitive adhesive, acrylic copolymer obtained by copolymerization of various acrylic monomers, is the most important type of resin-type pressure-sensitive adhesive. Compared with the above-mentioned rubber-type pressure-sensitive adhesive, they have many advantages: colorless and transparent appearance and good weather resistance; generally, good pressure-sensitive adhesive performance can be obtained without the use of additives such as tackifying resins, softeners and antioxidants, so the formula is simple; by copolymerization and cross-linking, pressure-sensitive adhesives that meet various performance requirements can be obtained. Therefore, in the past 20 years, this type of pressure-sensitive adhesive has developed very rapidly and has replaced the dominant position of natural rubber pressure-sensitive adhesive.

[0003] At present, the existing medical acrylic pressure-sensitive adhesive has strong adaptability, fast drying speed, strong adhesion to the substrate, good leveling and transparency, and solvent-based pressure-sensitive adhesive has good water resistance, especially high temperature and humidity resistance, cold resistance, etc., and durability, resistance to weak acids and weak alkalis are also good. However, when paying attention to the adaptability and drying speed of medical acrylic pressure-sensitive adhesive, it is ignored that toxic substances are easily produced in the preparation process of medical acrylic pressure-sensitive adhesive and allergic reactions may occur. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a novel preparation process of medical acrylic pressure-sensitive adhesive, which solves the problem of ignoring the toxic substances that are easily produced and the occurrence of allergic reactions during the preparation of medical acrylic pressure-sensitive adhesive.

[0005] To achieve the above object, the present invention is implemented by the following technical scheme: A preparation process of a novel medical acrylic pressure-sensitive adhesive comprises the following steps:

[0006] S1: Research on the synthesis process of medical acrylic pressure-sensitive adhesive

[0007] Medical acrylic pressure-sensitive adhesive was obtained by polymerization of butyl acrylate, α-ethyl acrylate, methyl acrylate, vinyl acetate, etc. The effects of ratio, initiator dosage, process conditions, etc. on product quality were studied, and a medical pressure-sensitive adhesive with good viscosity, non-toxicity, non-irritation, no skin damage when peeled off, and suitable water vapor permeability for transparent dressing was developed.

[0008] S2: Study on the biocompatibility of medical acrylic pressure-sensitive adhesive

[0009] The cytotoxicity of hydrophilic antibacterial polyurethane foam dressing was determined by referring to the provisions of "direct contact test" in GB / T16886.5-1997; the allergy test and irritation test were carried out according to the methods of "skin irritation test" and "closed sensitization test" in GB / T16886.10-2000.

[0010] S3: Study the coating process of medical pressure-sensitive adhesive and the appropriate amount of adhesive applied

[0011] The coating method of transparent sealing film obtained by compounding polyurethane film and pressure-sensitive adhesive was studied, the appropriate coating machine model and parameters were selected, and the appropriate coating amount was tested.

[0012] Preferably, in step S1, the monomer ratio of the raw material of medical acrylic pressure-sensitive adhesive is: 65% butyl acrylate, 5% 2-ethyl acrylate, 4% methyl acrylate and 30% vinyl acetate, the dosage ratio of the initiator is: 0.5% ammonium persulfate, the dosage ratio of the emulsifier is: 4% sodium dodecyl sulfate and 2% OP-10, the buffer is an appropriate amount of sodium bicarbonate, and the dispersant is an appropriate amount of distilled water.

[0013] Preferably, in step S1, the process conditions of the raw material of medical acrylic pressure-sensitive adhesive are as follows: (1): Different ratios of soft and hard monomers have a great influence on the peel strength of the pressure-sensitive adhesive. Increasing the ratio of monomers within a certain range can significantly improve the peel strength of the pressure-sensitive adhesive. However, if the ratio of hard monomers is too large, the peel strength will decrease instead. Taking all factors into consideration, the ratio of soft and hard monomers should be around 7:3. (2): Acrylic acid provides cross-linking functional groups for emulsion polymerization pressure-sensitive adhesive. Increasing the amount of acrylic acid can increase the cross-linking degree of the polymer. Too small a cross-linking degree is not enough to improve the performance of the pressure-sensitive adhesive. Too large a cross-linking degree results in excessive cohesive strength and insufficient affinity with the adherend. Taking all factors into consideration, an acrylic acid dosage of about 4% is more appropriate. (3): In this system, the amount of emulsifier should be between 6% and 8%.

[0014] Preferably, in step S1, the preparation method of the medical acrylic pressure-sensitive adhesive raw material is: at 60°C, start stirring, add 1 / 3 of the mixed monomer, all the emulsifiers, buffers, distilled water, and 1 / 2 of the initiator, keep for 30 minutes, slowly heat up to 78-80°C, start dripping the remaining 2 / 3 of the monomer and the remaining initiator, and complete the dripping within 2-2.5 hours; slowly heat up to 85-90°C, and keep for 1-1.5 hours, and then complete the discharge.

[0015] Preferably, in step S3, the coating process of the medical pressure-sensitive adhesive is to place a polyurethane film on a coating machine, and spray the pressure-sensitive adhesive evenly on the polyurethane film through a spray gun on the coating machine, the amount sprayed by the spray gun is 20-25g per square, and then the polyurethane film and the pressure-sensitive adhesive are compounded by a pressure roller on the coating machine to obtain a transparent sealing film.

[0016] The present invention provides a novel preparation process of medical acrylic pressure-sensitive adhesive, which has the following beneficial effects:

[0017] 1. The present invention studies the formula ratio of medical pressure-sensitive adhesive to produce a medical pressure-sensitive adhesive with good viscosity, non-toxicity, no irritation, no skin damage when peeled off, and suitable water vapor permeability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a process schematic diagram of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiment 1:

[0021] like Figure 1 As shown, the embodiment of the present invention provides a novel preparation process of medical acrylic pressure-sensitive adhesive, comprising the following steps:

[0022] S1: Research on the synthesis process of medical acrylic pressure-sensitive adhesive

[0023] Medical acrylic pressure-sensitive adhesive was obtained by polymerization of butyl acrylate, α-ethyl acrylate, methyl acrylate, vinyl acetate, etc. The effects of ratio, initiator dosage, process conditions, etc. on product quality were studied, and a medical pressure-sensitive adhesive with good viscosity, non-toxicity, non-irritation, no skin damage when peeled off, and suitable water vapor permeability for transparent dressing was developed.

[0024] S2: Study on the biocompatibility of medical acrylic pressure-sensitive adhesive

[0025] The cytotoxicity of hydrophilic antibacterial polyurethane foam dressing was determined by referring to the provisions of "direct contact test" in GB / T16886.5-1997. The allergy test and irritation test were carried out according to the methods of "skin irritation test" and "closed sensitization test" in GB / T16886.10-2000. The results of "allergy test" were evaluated as follows, and the primary irritation index (PI) of acute contact was determined according to the following provisions.

[0026] The primary irritation score of erythema and edema caused by the test materials for each animal at each specified time is added together and then divided by the total number of observations (the total is 6: two scores at each specified time). When a medium control is used, the primary irritation score of the medium control is calculated and subtracted from the primary irritation score of the test material to obtain the primary irritation score of each animal.

[0027] The observation data of 24h, 48h and 72h were used for calculation. The recovery observation data before the test or after 72h were not used for calculation. The sum of the scores of each animal and divided by the total number of animals was the primary irritation index.

[0028] The cumulative irritation index for multiple exposure tests shall be calculated according to the following provisions.

[0029] The irritation score of each animal at each specified time was added up and then divided by the total number of observations to obtain the irritation score of each animal.

[0030] The cumulative stimulation index is obtained by adding up the stimulation scores of each animal and dividing it by the total number of animals. The cumulative stimulation index type specified by the cumulative stimulation index is used to report the corresponding reaction type.

[0031] For any reaction, the maximum stimulus response, the time at which the reaction occurs, and the maximum reaction time should be determined.

[0032] S3: Study the coating process of medical pressure-sensitive adhesive and the appropriate amount of adhesive applied

[0033] The coating method of transparent sealing film obtained by compounding polyurethane film and pressure-sensitive adhesive was studied, the appropriate coating machine model and parameters were selected, and the appropriate coating amount was tested.

[0034] In step S1, the monomer ratio of the raw material of medical acrylic pressure-sensitive adhesive is: 65% butyl acrylate, 5% 2-ethyl acrylate, 4% methyl acrylate and 30% vinyl acetate, the dosage ratio of the initiator is: 0.5% ammonium persulfate, the dosage ratio of the emulsifier is: 4% sodium dodecyl sulfate and 2% OP-10, the buffer is an appropriate amount of sodium bicarbonate, and the dispersant is an appropriate amount of distilled water.

[0035] In step S1, the process conditions of the raw material of medical acrylic pressure-sensitive adhesive are as follows: (1): The different ratios of soft and hard monomers have a great influence on the peel strength of the pressure-sensitive adhesive. Increasing the ratio of monomers within a certain range can significantly improve the peel strength of the pressure-sensitive adhesive. However, if the ratio of hard monomers is too large, the peel strength will decrease. Taking all factors into consideration, the ratio of soft and hard monomers should be around 7:3. (2): Acrylic acid provides cross-linking functional groups for emulsion polymerization pressure-sensitive adhesive. Increasing the amount of acrylic acid can increase the cross-linking degree of the polymer. If the cross-linking degree is too small, it is not enough to improve the performance of the pressure-sensitive adhesive. If the cross-linking degree is too large, the cohesive strength is too large and the affinity with the adherend is insufficient. Taking all factors into consideration, the amount of acrylic acid used is more appropriate at around 4%. (3): In this system, the amount of emulsifier used is preferably 6% to 8%.

[0036] In step S1, the preparation method of the raw material of medical acrylic pressure-sensitive adhesive is as follows: at 60° C., start stirring, add 1 / 3 of the mixed monomer, all the emulsifiers, buffers, distilled water, and 1 / 2 of the initiator, keep for 30 minutes, slowly heat up to 78-80° C., start dripping the remaining 2 / 3 of the monomer and the remaining initiator, and complete the dripping within 2-2.5 hours; slowly heat up to 85-90° C., and keep for 1-1.5 hours, and then complete the discharge.

[0037] In step S3, the coating process of the medical pressure-sensitive adhesive is to place a polyurethane film on a coating machine, and spray the pressure-sensitive adhesive evenly on the polyurethane film through a spray gun on the coating machine, with the spray gun spraying 20-25 g per square meter, and then the polyurethane film and the pressure-sensitive adhesive are compounded by a pressure roller on the coating machine to obtain a transparent sealing film. The adhesion of the medical acrylic pressure-sensitive adhesive is not less than 18 kg, and the minimum 180° peel strength is 100 N / m, without adverse reactions such as irritation, allergy and cytotoxicity.

[0038] Embodiment 2

[0039] like Figure 1 As shown, the embodiment of the present invention provides a novel preparation process of medical acrylic pressure-sensitive adhesive, comprising the following steps:

[0040] S1: Research on the synthesis process of medical acrylic pressure-sensitive adhesive

[0041] Medical acrylic pressure-sensitive adhesive was obtained by polymerization of butyl acrylate, α-ethyl acrylate, methyl acrylate, vinyl acetate, etc. The effects of ratio, initiator dosage, process conditions, etc. on product quality were studied, and a medical pressure-sensitive adhesive with good viscosity, non-toxicity, non-irritation, no skin damage when peeled off, and suitable water vapor permeability for transparent dressing was developed.

[0042] S2: Study on the biocompatibility of medical acrylic pressure-sensitive adhesive

[0043] The cytotoxicity of hydrophilic antibacterial polyurethane foam dressings was determined by referring to the provisions of the "direct contact test" in GB / T16886.5-1997; the allergy test and irritation test were carried out according to the methods of the "skin irritation test" and "closed sensitization test" in GB / T16886.10-2000. The "direct contact test" adopted the following method in the process of determining the cytotoxicity of hydrophilic antibacterial polyurethane foam dressings: (1): First, prepare the cell suspension: After the passage (48-72)h cells were treated with digestive fluid, the adherent cells were suspended in the nutrient solution and the concentration of the cell suspension was adjusted to 3×10^5 cells / mL. (2): Prepare the cell monolayer on the plate: Add 10mL of the prepared cell suspension to each plate, and gently rotate the culture dish to make the cells evenly distributed on the bottom of the culture dish. Place it in a 37℃ constant temperature incubator containing 5% CO2 and culture it for 24h to make it a fused but not dense reticular cell monolayer. (3): Preparation of agar culture medium: Take the original cell culture medium, leave the fused cell suspension, add the mixed Eagles agar culture medium into the plate along the wall of the plate, 10mL per plate. Gently rotate the plate to make the agar culture medium evenly distributed, and let it solidify at room temperature. (4) Staining: There are two methods to choose from. Take 10mL of freshly prepared neutral red vital stain and gently place it in the center of the solidified agar surface. The dye should cover the entire surface. Avoid strong light and stain at 37℃ for 15 minutes. Tilt the plate and discard the excess dye; add neutral red dye to the melted Eagles agar medium (0.1mL of neutral red is added to 10mL of culture medium), mix and cover the cell monolayer. (5) Place the test sample: The sample should be placed immediately, no later than 1 hour after staining. Place the sample symmetrically on the agar surface. You can gently press it to contact the agar surface, but do not damage the agar surface. Place the culture in a CO2 incubator for 24 hours within 30 minutes of placing the sample. (6) Sample location: One negative sample, one positive sample and two identical samples are placed symmetrically on the agar surface of the culture dish, with the edge of the sample 15 mm away from the edge of the culture dish. At least two culture dishes are made for each test sample. (7) Evaluation of experimental results: Under a white background, observe the range of the decolorization area around and below the sample. The cell monolayer around and below the negative sample should reach the standard reaction, i.e., R = 0 / 0, and the positive sample should also reach the standard reaction, i.e., R = 2 / 2, otherwise the culture dish is discarded.

[0044] Reaction index: The reaction is expressed by the reaction index "R", that is,

[0045] R=Z / L

[0046] Wherein, Z is the regional index (as shown in Table 1), which is related to the size of the decolorization area; L is the cell lysis index (as shown in Table 2), which is related to the range of regional cell lysis.

[0047] Table 1 Regional indicators

[0048] Regional indicators Situation in the region 0 No discolouration is observed under or around the sample 1 The decolorization area is limited to the sample 2 Discoloration area diffused from the edge of the sample ≤ 5mm 3 Diffusion discoloration area from the edge of the sample ≤ 10mm 4 The discoloration area is >10mm from the edge of the sample, but does not cover the entire culture dish. 5 The decolorized area covers the entire culture dish

[0049] Table 2 Dissolution index

[0050] Dissolution index Condition within the depigmented area 0 No cell lysis was observed 1 Cell lysis in the decolorized area is less than 20% 2 The cell lysis in the decolorized area is between 20% and 40% 3 The cell lysis in the decolorized area is between 40% and 60% 4 The cell lysis rate in the decolorized area is between 60% and 80%. 5 The cell lysis rate in the decolorized area is more than 80%

[0051] The reaction index should be reported as two numbers (not a fraction), and the size of both indexes should be very obvious. For each sample, the average value of the regional index and the average value of the dissolution index should be reported. If one of the four values ​​of an index is missing for any reason, the test is abandoned. If only one is missing, the average value of the other three can be reported as the index. In the same test, the index size of 4 identical samples has a difference of 2 or more units. If the value is within 0-3, the test should be repeated; if the value is 4-5, it means that there is a highly diffuse toxic substance, and the test does not need to be repeated. For the reliability of the test, it is stipulated that each sample should be tested more than once, and finally the average value of its index should be reported.

[0052] S3: Study the coating process of medical pressure-sensitive adhesive and the appropriate amount of adhesive applied

[0053] The coating method of transparent sealing film obtained by compounding polyurethane film and pressure-sensitive adhesive was studied, the appropriate coating machine model and parameters were selected, and the appropriate coating amount was tested.

[0054] In step S1, the monomer ratio of the raw material of medical acrylic pressure-sensitive adhesive is: 65% butyl acrylate, 5% 2-ethyl acrylate, 4% methyl acrylate and 30% vinyl acetate, the dosage ratio of the initiator is: 0.5% ammonium persulfate, the dosage ratio of the emulsifier is: 4% sodium dodecyl sulfate and 2% OP-10, the buffer is an appropriate amount of sodium bicarbonate, and the dispersant is an appropriate amount of distilled water.

[0055] In step S1, the process conditions of the raw material of medical acrylic pressure-sensitive adhesive are as follows: (1): The different ratios of soft and hard monomers have a great influence on the peel strength of the pressure-sensitive adhesive. Increasing the ratio of monomers within a certain range can significantly improve the peel strength of the pressure-sensitive adhesive. However, if the ratio of hard monomers is too large, the peel strength will decrease. Taking all factors into consideration, the ratio of soft and hard monomers should be around 7:3. (2): Acrylic acid provides cross-linking functional groups for emulsion polymerization pressure-sensitive adhesive. Increasing the amount of acrylic acid can increase the cross-linking degree of the polymer. If the cross-linking degree is too small, it is not enough to improve the performance of the pressure-sensitive adhesive. If the cross-linking degree is too large, the cohesive strength is too large and the affinity with the adherend is insufficient. Taking all factors into consideration, the amount of acrylic acid used is more appropriate at around 4%. (3): In this system, the amount of emulsifier used is preferably 6% to 8%.

[0056] In step S1, the preparation method of the raw material of medical acrylic pressure-sensitive adhesive is as follows: at 60° C., start stirring, add 1 / 3 of the mixed monomer, all the emulsifiers, buffers, distilled water, and 1 / 2 of the initiator, keep for 30 minutes, slowly heat up to 78-80° C., start dripping the remaining 2 / 3 of the monomer and the remaining initiator, and complete the dripping within 2-2.5 hours; slowly heat up to 85-90° C., and keep for 1-1.5 hours, and then complete the discharge.

[0057] In step S3, the coating process of the medical pressure-sensitive adhesive is to place a polyurethane film on a coating machine, and evenly spray the pressure-sensitive adhesive on the polyurethane film through a spray gun on the coating machine, with the spray gun spraying 20-25 g per square meter, and then the polyurethane film and the pressure-sensitive adhesive are compounded by a pressure roller on the coating machine to obtain a transparent sealing film. The adhesion of the medical acrylic pressure-sensitive adhesive is not less than 18 kg, and the maximum 180° peel strength is 300 N / m, without adverse reactions such as irritation, allergy and cytotoxicity.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A novel process for preparing a medical acrylic pressure-sensitive adhesive, characterized in that: The following steps are involved: S1: Research on the synthesis process of medical acrylic pressure-sensitive adhesive Medical acrylic pressure-sensitive adhesive was obtained by polymerization of butyl acrylate, α-ethyl acrylate, methyl acrylate, vinyl acetate, etc. The effects of ratio, initiator dosage, process conditions, etc. on product quality were studied, and a medical pressure-sensitive adhesive with good viscosity, non-toxicity, non-irritation, no skin damage when peeled off, and suitable water vapor permeability for transparent dressing was developed. S2: Study on the biocompatibility of medical acrylic pressure-sensitive adhesive The cytotoxicity of hydrophilic antibacterial polyurethane foam dressing was determined by referring to the "direct contact test" in GB / T 16886.5-1997. The allergy test and irritation test were carried out according to the "skin irritation test" and "closed sensitization test" in GB / T 16886.10-2000. S3: Study the coating process of medical pressure-sensitive adhesive and the appropriate amount of adhesive applied The coating method of transparent sealing film obtained by compounding polyurethane film and pressure-sensitive adhesive was studied, the appropriate coating machine model and parameters were selected, and the appropriate coating amount was tested.

2. The preparation process of a novel medical acrylic pressure-sensitive adhesive according to claim 1, characterized in that: In step S1, the monomer ratio of the raw material of medical acrylic pressure-sensitive adhesive is: 65% butyl acrylate, 5% 2-ethyl acrylate, 4% methyl acrylate and 30% vinyl acetate, the dosage ratio of the initiator is: 0.5% ammonium persulfate, the dosage ratio of the emulsifier is: 4% sodium dodecyl sulfate and 2% OP-10, the buffer is an appropriate amount of sodium bicarbonate, and the dispersant is an appropriate amount of distilled water.

3. The preparation process of a novel medical acrylic pressure-sensitive adhesive according to claim 1, characterized in that: In step S1, the process conditions of the raw material of medical acrylic pressure-sensitive adhesive are as follows: (1): The different ratios of soft and hard monomers have a great influence on the peel strength of the pressure-sensitive adhesive. Increasing the ratio of monomers within a certain range can significantly improve the peel strength of the pressure-sensitive adhesive. However, if the ratio of hard monomers is too large, the peel strength will decrease. Taking all factors into consideration, the ratio of soft and hard monomers should be around 7:

3. (2): Acrylic acid provides cross-linking functional groups for emulsion polymerization pressure-sensitive adhesive. Increasing the amount of acrylic acid can increase the cross-linking degree of the polymer. If the cross-linking degree is too small, it is not enough to improve the performance of the pressure-sensitive adhesive. If the cross-linking degree is too large, the cohesive strength is too large and the affinity with the adherend is insufficient. Taking all factors into consideration, the amount of acrylic acid used is more appropriate at around 4%. (3): In this system, the amount of emulsifier used is preferably 6% to 8%.

4. The preparation process of a novel medical acrylic pressure-sensitive adhesive according to claim 1, characterized in that: In step S1, the preparation method of the raw material of medical acrylic pressure-sensitive adhesive is as follows: at 60° C., start stirring, add 1 / 3 of the mixed monomer, all the emulsifiers, buffers, distilled water, and 1 / 2 of the initiator, keep for 30 minutes, slowly heat up to 78-80° C., start dripping the remaining 2 / 3 of the monomer and the remaining initiator, and complete the dripping within 2-2.5 hours; slowly heat up to 85-90° C., and keep for 1-1.5 hours, and then complete the discharge.

5. The preparation process of a novel medical acrylic pressure-sensitive adhesive according to claim 1, characterized in that: In step S3, the coating process of the medical pressure-sensitive adhesive is to place the polyurethane film on the coating machine, and evenly spray the pressure-sensitive adhesive on the polyurethane film through the spray gun on the coating machine, the amount sprayed by the spray gun is 20-25g per square, and then the polyurethane film and the pressure-sensitive adhesive are compounded by the pressure roller on the coating machine to obtain a transparent sealing film.

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